If you read the transcript then what was most of the discussion about? Did they happen to the memo about the scope of the Mueller investigation?
28 CFR Part 600 - GENERAL POWERS OF SPECIAL COUNSEL
In this paragraph they describe the "jurisdiction" of an appointed special counsel. This is what requires the generation of the scope memo:
§ 600.4 Jurisdiction.
(a)Original jurisdiction. The jurisdiction of a Special Counsel shall be established by the Attorney General.
The Special Counsel will be provided with a specific factual statement of the matter to be investigated. The jurisdiction of a Special Counsel shall also include the authority to investigate and prosecute federal crimes committed in the course of, and with intent to interfere with, the Special Counsel's investigation, such as perjury, obstruction of justice, destruction of evidence, and intimidation of witnesses; and to conduct appeals arising out of the matter being investigated and/or prosecuted.
(b)Additional jurisdiction.
If in the course of his or her investigation the Special Counsel concludes that additional jurisdiction beyond that specified in his or her original jurisdiction is necessary in order to fully investigate and resolve the matters assigned, or to investigate new matters that come to light in the course of his or her investigation, he or she shall consult with the Attorney General, who will determine whether to include the additional matters within the Special Counsel's jurisdiction or assign them elsewhere.
(c)Civil and administrative jurisdiction. If in the course of his or her investigation the Special Counsel determines that administrative remedies, civil sanctions or other governmental action outside the criminal justice system might be appropriate, he or she shall consult with the Attorney General with respect to the appropriate component to take any necessary action. A Special Counsel shall not have civil or administrative authority unless specifically granted such jurisdiction by the Attorney General.
This further requires the SC to stay in line with the "scope: of the memo. It limits their authority:
§ 600.6 Powers and authority.
Subject to the limitations in the following paragraphs, the Special Counsel shall exercise,
within the scope of his or her jurisdiction, the full power and independent authority to exercise all investigative and prosecutorial functions of any United States Attorney. Except as provided in this part, the Special Counsel shall determine whether and to what extent to inform or consult with the Attorney General or others within the Department about the conduct of his or her duties and responsibilities.
https://www.law.cornell.edu/cfr/text/28/part-600
The order appointing the special counsel states that they have the authority to investigate, "any matters that arose or may arise directly from the investigation". The transcript clearly states that this investigation was "inherited" and did not "arise directly from this investigation".